I have a drop down menu at http://vr.flagstaffit.com/guide-service. If you mouse-over "courses" a drop down menu appears (AMGA, NAU, Women, etc). The background color for "courses" when moused-over is #333. The background for "courses" when mousing over the drop down is none (or gradient background shows up). I would like the background for "Courses" to be white when one moves the mouse down the drop down menu. Is that possible?

I've tried...
#nav_menu-7 ul li.current-menu-item a { background-color: #fff; }

and various others, but at this point I'm just guessing. Hoping for some help or at least an answer if it's not possible. I would like to make it so client can add drop downs to this wordpress menu and they work.

Thank you.